I just bought an S250 myself. The odomotor shows 37000 kilometers but in reality, it's probably around 50000.
The engine runs and sounds great (no weird noises). I checked the valves and the inlet valve was spot on at 0.1mm, the exhaust valve had zero play though. The engine has been running like this for the last four years (I know the previous owner), apparently Kymcos are designed to run for ages with tight valves.
There's almost no rust, nothing on the brake disks, rear springs, or any of the fasteners. There's some minimal surface rust on some of the frame welds and on the engine hanger. The age of the scooter is most clearly visible from the plastics, i.e. lots of scratches, some cracks, and lots of the OEM black parkers are missing or have been replaced with other types of screws.
It needs a few hundred euros worth of parts (belt, brake pads, air filter, etc. etc.). Axy, what is your experience with the 19gram rollers? I was thinking of ordering 19 gram Dr.Pulley weights. The OEM weights are 21 or 20 grams, not sure. Does anybody have any experience with various roller weights? What's optimal?
Thanks!